At $400 each, these lenses are an absolute steal! They are made of solid aluminum and have a very high quality finish. Combined with the Tilta Nucleus Nano, this is an amazing lens. I also bought the 12mm and 50mm lenses and plan to buy all 6 once the 65mm lens comes out. The lens uses inches. Also, this lens doesn't have a metric scale like the other two. Instead, it has imperial distance markers pointing both ways, so you can see it from either side. Additional information: - Closest focusing distance is 10 inches or 25 cm. Very suitable for use with the Glide Gear teleprompter. He can see both the top and the front bracket of the tablet. 25mm works fine.